{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2025-40009",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2025-04-16T07:20:57.151Z",
        "datePublished": "2025-10-20T15:26:55.208Z",
        "dateUpdated": "2026-05-11T21:40:42.885Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-05-11T21:40:42.885Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/proc/task_mmu: check p->vec_buf for NULL\n\nWhen the PAGEMAP_SCAN ioctl is invoked with vec_len = 0 reaches\npagemap_scan_backout_range(), kernel panics with null-ptr-deref:\n\n[   44.936808] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI\n[   44.937797] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\n[   44.938391] CPU: 1 UID: 0 PID: 2480 Comm: reproducer Not tainted 6.17.0-rc6 #22 PREEMPT(none)\n[   44.939062] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014\n[   44.939935] RIP: 0010:pagemap_scan_thp_entry.isra.0+0x741/0xa80\n\n<snip registers, unreliable trace>\n\n[   44.946828] Call Trace:\n[   44.947030]  <TASK>\n[   44.949219]  pagemap_scan_pmd_entry+0xec/0xfa0\n[   44.952593]  walk_pmd_range.isra.0+0x302/0x910\n[   44.954069]  walk_pud_range.isra.0+0x419/0x790\n[   44.954427]  walk_p4d_range+0x41e/0x620\n[   44.954743]  walk_pgd_range+0x31e/0x630\n[   44.955057]  __walk_page_range+0x160/0x670\n[   44.956883]  walk_page_range_mm+0x408/0x980\n[   44.958677]  walk_page_range+0x66/0x90\n[   44.958984]  do_pagemap_scan+0x28d/0x9c0\n[   44.961833]  do_pagemap_cmd+0x59/0x80\n[   44.962484]  __x64_sys_ioctl+0x18d/0x210\n[   44.962804]  do_syscall_64+0x5b/0x290\n[   44.963111]  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nvec_len = 0 in pagemap_scan_init_bounce_buffer() means no buffers are\nallocated and p->vec_buf remains set to NULL.\n\nThis breaks an assumption made later in pagemap_scan_backout_range(), that\npage_region is always allocated for p->vec_buf_index.\n\nFix it by explicitly checking p->vec_buf for NULL before dereferencing.\n\nOther sites that might run into same deref-issue are already (directly or\ntransitively) protected by checking p->vec_buf.\n\nNote:\nFrom PAGEMAP_SCAN man page, it seems vec_len = 0 is valid when no output\nis requested and it's only the side effects caller is interested in,\nhence it passes check in pagemap_scan_get_args().\n\nThis issue was found by syzkaller."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/proc/task_mmu.c"
                    ],
                    "versions": [
                        {
                            "version": "52526ca7fdb905a768a93f8faa418e9b988fc34b",
                            "lessThan": "ca988dcdc6683ecd9de5f525ce469588a9141c21",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "52526ca7fdb905a768a93f8faa418e9b988fc34b",
                            "lessThan": "a2cb8818a3d915cd33a1e8b2babc1bb0c34862c3",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "52526ca7fdb905a768a93f8faa418e9b988fc34b",
                            "lessThan": "28aa29986dde79e8466bc87569141291053833f5",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/proc/task_mmu.c"
                    ],
                    "versions": [
                        {
                            "version": "6.7",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.7",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.50",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.16.10",
                            "lessThanOrEqual": "6.16.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.17",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.7",
                                    "versionEndExcluding": "6.12.50"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.7",
                                    "versionEndExcluding": "6.16.10"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.7",
                                    "versionEndExcluding": "6.17"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/ca988dcdc6683ecd9de5f525ce469588a9141c21"
                },
                {
                    "url": "https://git.kernel.org/stable/c/a2cb8818a3d915cd33a1e8b2babc1bb0c34862c3"
                },
                {
                    "url": "https://git.kernel.org/stable/c/28aa29986dde79e8466bc87569141291053833f5"
                }
            ],
            "title": "fs/proc/task_mmu: check p->vec_buf for NULL",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}